The subject matter disclosed herein relates to systems and method for calibrating current transducers. More specifically, the subject matter disclosed herein relates to calibrating phase and sensitivity characteristics of a current transducer output.
A current transducer generally includes a winding around a magnetic core. When the current transducer is placed around a cable or other type of conductor, a time-varying (e.g., alternating current) current conducting through the cable may produce a time-varying magnetic field in the magnetic core. The magnetic field may then induce a current in the winding of the current transducer. The current in the winding may be proportional to the current conducting through the cable. As such, the current in the winding may be used to measure a magnitude and direction of the current conducting in the cable.
However, conventional current transducers have relatively high tolerances in their electrical (i.e., resistance) and magnetic (i.e., inductance) characteristics due to magnetic properties of the materials inside the current transducers and the manufacturing process used to create the current transducers. That is, each current transducer may have its own sensitivity or tolerance levels based on its inherent characteristics. These sensitivity levels produce a higher degree of uncertainty in an electrical signal output by each current transducer. Additionally, these inherent characteristics may also introduce a phase shift between the signal output by the current transducer and a measured current. Accordingly, it would be beneficial to calibrate current transducers to perform at specified or known tolerance levels, and phase shifts.
Moreover, conventional current transducers use a steel tape to shield internal components, such as a current sensor, against various types of noise (e.g., electrical or magnetic noise). That is, the steel tape may be wound around a piece of metal to form a shield that may be placed around the current sensor. Using four steel tape-wound shields, each side of the current sensor may be shielded against magnetic disturbances and noise. However, creating each steel tape-wound shield is a complex process that may easily be mishandled, thereby jeopardizing the integrity of the overall shield around the current sensor. Accordingly, it would be beneficial to provide a more easily manufactured apparatus for shielding the components inside the current transducer.